From ultracold electrons to coherent soft X-rays

TL;DR

This paper proposes a novel, compact soft X-ray source based on inverse Compton scattering of laser-cooled atomic gases, enabling coherent, high-flux X-ray generation without large-scale facilities.

Contribution

It introduces a new method for producing coherent soft X-rays using laser-cooled gases and micro-bunching techniques, reducing reliance on large-scale synchrotrons.

Findings

Conceptual design of a tabletop coherent soft X-ray source.

Potential for high photon flux and coherence at small-scale facilities.

Feasibility of micro-bunching via spatial modulation and RF compression.

Abstract

Electromagnetic radiation in the soft x-ray spectral range ($1-100~\rm{nm}$ wavelengths or $0.01-1~\rm{keV}$ photon energies) is rapidly gaining importance in both fundamental research and industrial applications. At present the degree of coherence and the average photon flux required by advanced applications is only available at large-scale synchrotron facilities and Free Electron Lasers (FELs), severely limiting the range of applications. We propose a fully coherent soft x-ray source, based on Inverse Compton Scattering (ICS) of electron bunches created by photoionization of a laser-cooled and trapped atomic gas. By combining spatial modulation of the photoionization process with radiofrequency bunch compression techniques, micro-bunching at soft x-ray wavelengths and thus coherent amplification can be realised, resulting in a soft x-ray table-top Compton light source.